Machines for forming and pressing sheet metal and profiles



Feb; 9, ,1960

w. ECKOLD 2,924,131 MACHINES FOR FORMING AND PRESSING SHEET METAL-AND PROFILES v 3 Sheets-Sheet 1 Filed Aug. 20, 1957 /NNNNAVNNNNWM Feb. 9, 1960 w. ECKOLD 2,924,131

MACHINES FOR FORMING AND PRESSING SHEET METAL AND PROFILES s Sheets-Sheet 2 Filed Aug. 20, 1957 Feb. 9, 1960 w. ECKOLD 2,924,131

MACHINES FOR FORMING AND PRESSING SHEET METAL AND PROFILES Filed Aug. 20, 1957 3 Sheets-Sheet 3 WWM' MACHINES FOR FORMING AND PRESSING SHEET METAL AND PROFILES Walter Eckold, St. Andreasberg, Oberharz, Germany Application August 20, 1957, Serial No. 679,289 Claims priority, application Germany August 30, 1956 7 Claims. (Cl. 78-36) .VThe present invention relates to machines for forming and pressing sheet metal and profiles which operate by means of press tools acting at a high speed upon the material. The high speed at which they operate calls for special care in the maintenance of such machines as far as adequate lubrication of their moving parts is concerned, particularly if high working pressures are used; otherwise these parts will be subjected to excessive wear, or they may even seize and thus render the. whole machine unserviceable.

An object of the invention is to make the operation of the machines practically independent of the need for lubrication, and at the same time so to simplifythe design of such machines that their manufacture and assembly becomes simple and economical.

According to the present invention, in a machine for forming and pressing sheet metal and profiles which operates by means of a press tool acting at high speed,

'movement and power are transmitted to the press tool by means of a floating, double-ended lever inside the housing of the machine, the said lever oscillating by executing a rolling movement over the surface of apressure pad.

.is preferably inline with the point of application of pressure by the press tool. The plate may be supported by a resilient mass such as a rubber mass to which the plate is bonded, the mass also being bonded to the ram.

Several embodiments of theinvention will now be described in greater detail by way of example with reference to the accompanying drawings of which:

Fig.1 shows a longitudinal section through a machine according to the invention,

vFig. 2 is a part section on the line A-A of Fig. 1

.drawn on a larger scale,

Fig. 3 is a horizontal section of the embodiment of Fig. 1,

Fig. 4 is a longitudinal part section through the top of another embodiment of the invention,

Fig. 5 is a section on the line B--B of Fig. 4,

Fig. 6 shows the drive of a twin machine,

Fig. 7 is a detail showing a modification,

Fig. 8 shows a further type of drive,

Fig. 9 is a section on the line C-C of Fig. 8, c. Fig. 10 shows the drive of Fig. 8 used in a twin machine, and t Fig. 11 is a section on the line D D of Fig. 10.

In the embodiment of the invention shown in Figs. 1 to t 3W w 3, a double-ended lever 2 floats inside a housing 1 of the machine, that is, the lever does not turn about a 2 2,924,131 'Fatented F b. 9,1960

ice,

hinged to a flexible flat plate 3 which stands upright on edge, whilst the other forked end 2" of the lever carries 7 an eccentrically-mounted pulley 4. The pulley or wheel 4 is eccentrically mounted on the lever 2 at the end 2". The lever 2 rotates about a pressure pad 5 which is in the form of a threaded spindle and is'adjustable for height by means of a hand wheel 6. In this arrangement, the actual support for the lever 2 is provided by the end 7 of the spindle having a cylindrical contact surface 7', over which the lever 2 rolls when it oscillates. Fixed to each side of the support 7 are lugs 7' forming a fork in which the lever 2 moves. Adhering to the insides of these lugs are rubber blocks, which are preferably precompressed and which fill the space between the lugs 7" and the sides of the lever 2. If these rubber blocks are pre-compressed in an upward direction, all looseness between the support 7 and the rolling surface of the lever 2 in contact with it is eliminated. Further flexible support for the lever 2' is provided by another pair of rubber-metal elements 8. Those elements are attached, on the one hand to the central web 2". of the lever 2 which is formed by recesses at each side of the lever, and on the other hand to the sides of the housing 1. These rubber connections are pre-compressed such that they always press the pulley 4 against a pulley or wheel 9 of a motor 11. This effect can be reinforced, or alternatively can be provided, by a roller arch 10, which is supported resiliently by a rubber torsion bush 10'. vWith regard to the motor drive, another possibility is to mount the pulley 9, which is driven by the motor 11, eccentrically, in which case the pressure roller 4 would run centrically. If one or both of these transmission elements were to be made of some hard plastic or laminated material noise during the operation of the machine wouldv be largely eliminated. The machine has a ram in the form of a hollow cylinder 13 having a slot 13' through which the end 2 of the lever passes into the inside of the cylinder. The eccentric drive formed by 4 and 9 causes the lever arm 2' to reciprocate and the motion of this arm is transmitted through the ram and the fiat plate 3 to a press tool 12. The fiat plate 3 is freely supported on the bottom 13" of the hollow cylinder 13 and is held resiliently inside a rubber cushion 14 to which the plate is bonded. The cushion 14 is'also bonded to the internal surface of the cylinder. At its top the hollow cylinder 13 is closed by a screwed plug 15. This plug exerts such a pressure on an intermediate rubber spacer 16 that all play at the contact edges of the fiat plate 3 will be prevented.

The ram of the machine is thus made in the form of a hollow cylinder, and the inertia of the parts which have to be accelerated at every stroke is considerably reduced in comparison with the solid shape formerly used for such parts, so that the vibrations set up by the ma chine are greatly reduced.

A blank 17 is inserted between the upper press 'tool 12 and a fixed bottom press tool 12'. If the operation is to produce compressive or tensile deformation of the sheet, it is preferable to use for this purpose tools with clamping jaws moving in opposite directions. The motor 11 is switched on, actuating the eccentric drive 4, 9, and the upper press tool 12 will move up and down with short strokes and will, in conjunction with the lower tool 12, cause the compressive or tensile deformation of the blank. Although thrusts of the order of several tons are being transmitted, the whole system remains flexible and does not require any lubrication. It will be seen that the centre line of the plate 3 is in line with the point of application of pressure by the press tool 12.

Figures 4 and 5 show an embodiment of the invention in which the support of the pressure pad 5 is provided byea movable'and easily exchangeable cap 18 having a .cylindrical contact surface..18. .Anyeceentric power transmission which might possibly occur will, in this way, be automatically eliminated. Apart from that, rubber- "metal elements are 'againrrprovidedzin this embddimeht 1 to support lever zresiliently. and' whichexert a forcegsuch l asto prevent any-play betweenrthe rolling? contact .fac'es. :In order to reducewearof the? contact face of :the'lever [2 it is provided witha hardened inset 21 which can easily be exchanged when necessary. Insorderxto provide a 'sati'sfactoryhinge (between the'upper edge of :the flat plate '3 and the under side of the end 2 of the lever, a ball.22 is provided which is located in sphericalwseat- .ings in both these parts.

Fig. 6 shows the principle of a twin machine," in which aQcentral driving pulley 23 supplies the. power-for the 7 two press units 12 and 12..':The two levers 2 goingto -the left and to the rightare here each driven by an eccentric 4. The purpose of the hand wheels 4 is as berfore. to enable the travel of the. press tools to be ad- I justed.

Fig. 7 shows part of an embodiment of the invention in which the flat plate' 3 is 'placed eccentrically with respect to the hollow cylinder 13. This arrangement would be usefulif the press tools, as shown in Figs. 1 and6, are also mounted eccentrically in the machine but if nevertheless it is desired to transmit pressure to them on as accurately central a line as possible.

In the embodiment of the invention part of which is :shown in Figs. 8 and' 9, the reciprocating motion of the eccentricsis transmitted by'a connecting link 24 having Figs. 10 and 11 show the actuating mechanism of the embodiment of Figs. 8 and 9'applied to a twin machine.

The contact surface 24" of the connecting link 24xis here made wide enough so that the ends 2" of the levers of both halves of the machine canbe accommodated on 1 top of it. Apart from this, the same type of rubbermetalelementsZS as in Figs. Sand 9 are provided with the two ends 2" of the levers arranged between them.

In order to prevent vibrations as far as' possible duringthe operation of the machine, all rotating parts, such as the pressure rollers; eccentrics and pulleys are as accurately balanced by recesses, drilled holes, lead insets etc. as possible, which contributes further towards noiseless running of the machine. Resiliently mounted balancing weights may also be provided in the sidewalls of the housing for the same purpose.

The housing of themachine can besplit longitudinally in two halves whichare screwed together. The housing is best closed at the front by 'a separate cover. 26'which forms, togetherwith the housing or: with the halves of the housing, a bearing for the support ofthe reciprocating machine ram.. This would simplify considerably the assembly of the various parts of the machine; in some cases their assembly would not be possible without such an arrangement at all. i

l In contrast to the imbodiments of the invention shown in the' drawings, the motor drive of the machine could also actuate the lower tools; in that case, a twin machine might be so arranged thaton one side the upper tool and on the other side the lower tool is driven by the motor.

The housing 1 is supported by a rigid pedestal 27. .On the other hand, the housing might also be supported in a movable frame suitable fordifferent working positions. These machine elements'used' for the transmission. of power in the machines described above may have to trans- .rnit forces amounting to several tons and by. abandoning the former practice of supporting them in fixed pivots it becomes possible to make the .transmission'of power so flexible thatthe :sndden impact loadstoiwhich they had Here again, both parts are 'so constrained formerly been subjected are eliminated, so that much steadier and quieter. running .will. be achieved .asa 01156.

quence.

What I claim is:

1. A machine for forming and pressing sheet metal casing having oneend in contact with. the movable press tool, a wheel mountedon the "other end'of the lever with the levermounted eccentrically relative' to .theicenter axis of the last-mentioned wheel, a fulcrum support in the casing in contact with the-lever 'and which is in the form of a pressure pad, and means in the casing in contact with the last-mentioned wheel sothat when the motor 1 driven wheel rotates the last-mentioned wheel, the latter will oscillate the levenduedolhe; eccentric connection andthereby transmit,intermittent-power forces to 'the movable press tool with the 'means maintaining the tw wheels in contactwith eachother. 1

2. A machine according to claim lyin which the means is in the form of a roller arch in contact with the first-mentionedflwheel tomaintain the-"wheels in contact with each other. t '3 t 3. A machine according to claim 1, in whichrubber elements are provided on each side of the lev er approxi- 1 mately intermediate the ends and supported by the casing.

4. A machine .according to. claim 1, in which rubber rubber and with a metal plateon: the-casing and lever with the rubber element in between. 1

5. A. machine for forming and pressing sheet "metal andprofil'es comprising-a' casing; a stationary press to'ol the ram of the movablettool'.

securedin the casing, a pres's' tool=in theiorm of a ram mounted in thecasingto be movable therein to' cooperate with and movable toward the st'ationary press tool with short strokes, a motor-idriven wheel mounted in the casing, 21 :double J ended 1 ilever mounted. to float in the casing having one endfin': contact with themovable press tool, a wheel mounted on the other. end of the leverjwith the lever mountedecc'entrically relative to the center axis of the lastmentioned wheel,r1a: tulcrum support inj-the 1 casing in contact'with th'elleven and which is in the'forr'n of a pressure pad, andt me'ans 'infi the casing "to-maintain vthe'wheelsin contactwith each othen saidmeans being in the form of annarch'edLmembenwith "atfleast two rollers bearing 1 on the ilast-mehtioned wheel.

6. A. machine: accordingfitoiclaim 1', in whic h wflat ,plate is provided securedainxthe? movable press tool to contact theend-of the lever in contact with thelmovable .tool. i l

7. A machine accordingatdclaim twin which-a flat plate is provided secur'edin the movable press tool t'ocon tact the end of the lever inucoritact with the movable tool, the flat plate be'ing supported'byand boiided lto a rubber cushion, the said rubber cushion being bonded to 1 "(Other refe re'ncesyon following page) UNITED STATES PATENTS Burgess June 6, 1916 Leckinger Apr. 1, 1919 Beach July 27, 1920 Sustarich June 12, 1923 Osborne Feb. 28, 1928 Klocke Nov. 11, 1930 McClean July 7, 1931 6 Rockenfield June 7, 1932 Blackmore et a1 July 13, 1943 Jackson Jan. 25, 1949 De Witt et a1 Feb. 9, 1954 FOREIGN PATENTS France Aug. 3, 1942 Germany Oct. 8, 1953 

